GB3NGI Radio Beacons


144 MHz Beacon

Frequency: 144.482 MHz
ERP: 21dBW
Heading: 45° and 135°
Locator: IO65VB27
Location: Slieve Annora
Keeper: Gordon Curry GI6ATZ



The 144 MHZ Beacon uses the Next Generation Beacon hardware: -
http://www.rudius.net/oz2m/


BeaconParts


The reference 10 MHz Oscillator for the beacon source is derived from a GPS Disciplined Oscillator designed and built by James Miller G3RUH. More information on the GPSDO can be found here: -

http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm

The beacon generates both CW and JT65b coding allowing the transmitted signals to be decoded either by ear or by the WSJT software written by Joe Taylor K1JT: -

http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html

The Beacon has an RF output power of 20 watts.
The beacon transmits JT65b on the even minutes and CW on the odd minutes in the following sequence: -

00:01 – 00:51 GB3NGI IO65VB in JT65b mode
00:52 – 01:03 GB3NGI IO65VB in CW
01:04 – 01:29 Plain Carrier
01:30 – 01:42 GB3NGI IO65VB in CW
01:43 – 02:00 Plain Carrier

The sequence then repeats

To decode the JT65b, tune the carrier to obtain a tone of 1500Hz with the receiver set to USB, and the dial frequency reading 144.4805. The JT65b will then be tuned in correctly.


The antennas used for the 144 MHz beacon are a pair of 4 element Jaybeam 7029145 yagis phased using a Tonna two-way power divider. The antennas are connected to the transmitter using LDF-450 cable. The yagis are on headings of 45° and 135° and are 10 metres above ground level.




If you would like to contribute to the upkeep of the GB3NGI Beacon Cluster then please click on the link below

Website Design Jim McConnell
www.jimkells.com